1. Field of the Invention
The present invention relates to a disc recording/reproducing apparatus, and more particularly to a disc recording/reproducing apparatus suitable for controlling the apparatus or other external devices in accordance with control information recorded in a U-TOC area of a disc, the U-TOC area being a table of contents (TOC) area in which a user writes data.
2. Related Background Art
A recordable MD disc has a spiral groove engraved in the record area of the disc. The engraved spiral groove has a swell so that a swell frequency of 22.05 kHz can be detected when the disc rotates at a standard rotation speed. Therefore, the rotation of MD is controlled by maintaining the detected frequency to be 22.05 kHz. The swell is FM modulated by address information at the deviation frequency of 1 kHz. This address information is used to detect a particular position of the spiral groove. In the recordable MD address system, a logical access is executed in units of a cluster containing 36 sectors. Namely, the address of a sector is represented by a 16-bit cluster address and an 8-bit sector address. For example, an address (11FFH: 1FH) indicates the cluster address of 11FFH and the offset sector address 1FH of the cluster at 11FFH. The disc area of a recordable MD includes, as shown in FIG. 3, a lead-in area, a U-TOC area, and a recordable user area. A music program is recorded in the recordable user area. TNO-1 to TNO-255 are identifiers to be assigned to a plurality of music programs. For example, if a music program TNO-5 is recorded in the region from a start address 1F0BH: 0AH to an end address 2A2AH: 2BH, the identifier TNO-5 and its associated start address are stored in section 0 of the U-TOC area. Optionally, the identifiers and the music program names are stored in section 1 of the U-TOC area, as illustrated in FIG. 4. The U-TOC is therefore an information management table for music programs stored in the recordable user area.
ASCII code characters can be recorded in sector 1 of the U-TOC area and added to each TNO. However, in a conventional MD disc recording/reproducing apparatus, character information recorded in sector 1 of the U-TOC area of an MD has been used only for displaying character information on the display unit of the apparatus.